The Safari tab bar now behaves the way the tab bar in Camino does. You can open a URL by drag-and-dropping it onto a tab (whether the tab is in the foreground or in the background). If you drag and drop a URL somewhere on the unused area of the tab bar, Safari will create a new tab for that url.

[robg adds: This is a long-awaited improvement; my old habits from other browsers were not going away, and I was always surprised when Safari didn't behave as expected when I dropped a URL on the tab bar.]